Apr 7, 2025
2:15pm - 2:30pm
Summit, Level 4, Room 439
Hongbin Yang1,Jinkwon Kim1,Darrell Schlom1,2,3,David Muller1,2
Cornell University1,Kavli Institute at Cornell for Nanoscale Science2,Leibniz-Institut fur Kristallzuchtung3
Hongbin Yang1,Jinkwon Kim1,Darrell Schlom1,2,3,David Muller1,2
Cornell University1,Kavli Institute at Cornell for Nanoscale Science2,Leibniz-Institut fur Kristallzuchtung3
Sr
2CuO
3+δ is a unique cuprate superconductor. It superconducts in the extremely over doped regime with a Tc up to 95 K. Some fundamental aspects about this material remains unknown. For example, the position and distribution of oxygen vacancies in the lattice is still an open question. Here, we use multislice electron ptychography (MEP) to image the atomic structure of an epitaxial Sr
2CuO
3+δ film grown by molecular beam epitaxy. MEP is a phase-retrieval method that reconstructs the atomic potentials from the full scattering distribution of a scanned electron beam. Our findings reveal that the apical oxygen sites are fully occupied, and the oxygen vacancies reside in the Cu-O plane. Partially occupied oxygen sites are also directly observed in the reconstructed images, enabling quantification of the doping level. Additionally, we observe domains throughout the film, ranging from about 10 to 100 nm in size, likely formed due to varying oxygen occupancy. Finally, we will discuss the electronic structure based on the near edge fine structure of O-K edges in electron energy loss spectroscopy.